Browsing Photographers' Formulary I looked at Edwal 12 last week, only to discover:
EDWAL 12, 1L: Metol(6gm); Sodium Sulfite(90gm); p-phenylenediamine(10g); Glycin(5g)
Same incredients in the same (all-important) order, and shows amounts!

But I'm posting because of Hardy's account of an assignment for PICTURE POST (in the Photo-Histories link above):
Hopkinson asked Bert to do a shoot on the street shelters. Bert photographed a Newcastle brick-lined tunnel during the Blitz
handholding his Leica at 1/4 of a second. Hardy put the film in his super-soup. Knowing the images were underexposed, he doubled his usual processing time from sixteen to thirty minutes. Another half hour in the super-soup produced the faintest of highlights [viewing with green light].
Hardy goes off to his Mum's to make some tea, falls asleep. By the time he got back to the darkroom the films had been stewing for four hours,dense and very grainy negatives.
Hardy even felt the lighting in the images emanated a Rembrandt-like quality.

There is actually very little that developers can do. Some give more speed, some give finer grain. The differences between the best and worst are not huge. Noticeable to the critical user, to be sure, but not huge. The amount of exposure and development is what matters most.